Fuel feeder



E. C. MILLER FUEL FEEDER Dec. 11, 1956 Filed Nov] 5, 1963 INVENTOR [4515C. MILLER BY ATTORNEY FUEL FEEDER Earle C. Miller, Worcester, Mass.,assignor to Riley Stoker Corporation, Worcester, Mass., a corporation ofMassachusetts This invention relates generally to a fuel feeder and moreparticularly to an apparatus for regulating the movement of bulky fuelfrom a storage bunker to a furnace.

There are many situations in industry where it is good practice, fromthe view-point of economy, to produce steam for heating and processingfrom one of thebyproducts of the industry. One industry where such asituation exists is in the refining of sugar where the fibrous refuseknown as bagasse may be burned to produce steam for the sugar refiningprocesses. The lumber industry provides another such situation, sincethe scrap wood may be hoggedinto small pieces and used to produce steamfor the power necessary to drive the wood working machinery. In theburning of refuse, however, it is often necessary to have available areservoir of refuse which can be used to maintain the boiler load shouldthe source or" refuse be interrupted temporarily. There have not beenany satisfactory apparatus for providing for the feeding of moistfibrous refuse such as bagasse, hogged wood, etc., because this materialpacks easily and hangs up or arches over in the hoppers. The presentinvention obviates the difficulties experienced with prior art fuelfeeders in a novel manner.

It is therefore an outstanding object of the invention to provide a fuelfeeder for refuse which will not be rendered inoperative by clogging.

Another object of this invention is to provide a fuel feeder for refusewhich will furnish storage space for temporary interruption of thesource of refuse and which is not subject to clogging.

It is a still further object of the present invention to provide a fuelfeeding hopper having a live side for separating matted refuse in thehopper.

It is another object of the instant invention to provide a fuel feederwhich will provide storage for the fuel and at the same time will feedthe fuel evenly without clogging.

Although the novel features which are believed to be characteristic ofthis invention will be particularly pointed out in the claims appendedhereto, the invention itself, as to its objects and advantages, the modeof its operation and manner of its organization may be better understoodby referring to the following description taken in connection with theaccompanying drawings forming a part thereof, in which:

Figure 1 is a sectional view of the apparatus of the invention used inconjunction with a steam generating unit, the section being taken on theline II of Figure 2, and

Figure 2 is an elevational view of the apparatus of the inventionlooking toward the furnace.

Like reference numerals denote similar parts in the several figures ofthe drawings.

Referring to Figures 1 and 2, the fuel feeder of the invention,designated generally by the reference numeral 10, is shown mounted abovea pneumatic spreader 11, both feeder and spreader being mounted on thewall 12 i United States Patent" 2,773,629 Patented Dec. 11, 1956 of thefurnace of a steam generating unit. The pneumatic spreader 11 is of thetype shown and described in U. S. Patent No. 2,602,706, which issued toEarle C. Miller et al. on July 8, 1952. This spreader is mounted overthe opening 13 in the furnace wall and is provided with a distributingplate 14, the angularity of which is adjusted by a handle 15. A nozzle16 is connected to a source of air, not shown, under substantialpressure by a conduit 17. Extending upwardly from the mouth of thenozzle 16 and from above the distributor plate 14 is a chute 18. Thechute 18 is narrow at the lower end and is enlarged at the upper end.The chute 18 is fastened to the furnace wall 12 and extends therethroughat a substantial angle.

The upper end of the chute 18 is attached to a trough 19 forming a partof the fuel feeder 10. The chute is attached to the lower end of thetrough adjacent the furnace at which point an opening 20 is provided.Extending longitudinally of the trough are a pair of conveyor screws 21and 22 which are positively driven by means not shown. The sizes of thescrews 21 and 22 are such that they touch each other centrally of thetrough and have their outer portions closely adjacent the bottom of thetrough and the sides of the trough. The screws terminate over theaperture 20 and the trough 18 and are driven in such a manner as toconvey mathe hopper are parallel to one another and have a somewhattrapezoidal shape. A fourth wall 27 of the hopper is of course adjacentthe furnace wall 12. At its lower edge it is fastened to the trough 19and it extends upwardly and away from the furnace at a somewhat lesserangle than would be required to match the angle of the wall 24. However,at its upper portion the wall 27 is bent into a somewhat cylindricaltransverse surface 28 so that the wall 27 is somewhat horizontal at itsuppermost portion. To the top of the hopper 23 and fastened to the topedges of the walls 24, 25, 26, and 27 is a chute 29 of rectangularcross-section which extends vertically upwardly and is attached at itsupper end to a source of refuse, not shown. Transversely of the hopper23 and overlying the opening 20 is a shaft 30 which is driven by means,not shown, and which has keyed thereon a sprocket drum 31. A similarshaft 32 and sprocket drum 33 are mounted at the upper portion of thehopper and underlie the point of juncture of the wall 27 and the chute29. Around the drums 31 and 33 extends an endless belt 34. This belt maybe formed of link chain and may be provided with lugs 35. A stiffeningplate 36 is mounted inwardly of the belt 34 and serves to restrain anytendency of the inner run of the belt to move toward the furnace.

The operation of the invention will now be understood in view of theabove description. The bulky refuse will enter the apparatus through thechute 29 and fall into the hopper 23. The screws 21 and 22 by rotatingwill carry portions of the fuel which are in the lower part of thehopper toward the opening 20. The fuel falls through the opening 20 downthe chute 18 and is blown into the furnace by the impingement of airfrom the nozzle 16. The adjustment of the distributing plate 14 by meansof the handle 15 determines the type of distribution of fuel within thefurnace. Because of the desirability of having a storage of fueladjacent the spreader 16 to take care of the contingency of failure ofthe supply of fuel down the chute 29, it is desirable to fill the hopper'23. However, because of the fibrous moist nature of the refuse and thepressure of fuel in the chute 29 there is a tendency for the fuel toform a tight, matted mass within the hopper '23. When this happens, thescrews 21 and 22 will not successfully tear particles of refuse from themass and the fuel feed to the spreader 16 is interrupted. However, theaction of the endless belt 34 is to tear layers of refuse from the massand drop them through the opening 20, thus by, in effect, providing thehopper 23 with a moving wall, the natural tendency of the refuse fuel tomat and hang up inside the hopper is prevented. One of the reasons whyfuel of this type jams in hoppers and conduits is because of thepressure on the fuel causing the fuel to press out wardly against thewalls. The outward pressure against the walls of the hopper or the likeprevents the fuel from falling downwardly in the desirable manner. Itcan be seen then that by providing a movable wall in the manner of theinvention, such action becomes impossible.

While certain novel features of the invention have been shown anddescribed and are pointed out in the annexed claims, it will beunderstood that various omissions, substitutions, and changes in theforms and details of the device illustrated and in its operation may bemade by those skilled in the art without departing from the spirit ofthe invention.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A fuel feeder for supplying moist, bulky refuse to a furnacecomprising a hopper having at least one inclined side, an endless beltproviding an inclined downwardlyrnoving surface in opposition to thesaid inclined side, the moving surface and the said wall diverging in adownward direction, a screw type conveyor underlying the hopper and adownwardly directed chute having its upper end underlying the dischargeend of the screw type conveyor.

2. A fuel feeder for supplying moist, bulky fuel to the furnace of asteam generating unit comprising a hopper having an opening at its upperend to which is connected a vertical chute through which the fuelarrives, a trough underlying and connected to the lower end of thehopper, the trough having a pair of driven conveyor screws mountedtherein and having an opening at the discharge end of the screws towhich a downwardly directed chute is attached, the hopper having aninclined wall, a driven endless belt mounted in the hopper and having astraight run providing a downwardly-moving surface in opposition to thesaid inclined wall, the inclined wall and the moving surface divergingin a downward direction, the lower end of the moving surface overlyingthe discharge end of the screws, while the lower end of the inclinedwall overlies the other ends of the screws.

3. A fuel feeder for supplying moist, bulky refuse to a furnacecomprising a hopper having at least one inclined side, an endless beltproviding an inclined down- Wardly-moving surface in opposition to thesaid inclined side, the moving surface and the said wall diverging in adownward direction, a horizontally-traversing conveyor underlying thehopper, and a downwardly-directed chute having its upper end underlyingthe discharge end of the conveyor.

References Cited in the file of this patent UNITED STATES PATENTS426,689 Silvertooth Apr. 29, 1890 1,835,989 Hofit et al Dec. 8, 19311,862,752 Jones et al. June 14, 1932 2,362,315 Schultze NOV. 7, 1944FOREIGN PATENTS 238,901 Germany Oct. 4, 1911

